PYONGYANG, North Korea (AP) - Defying U.N. warnings, North Korea conducted its third nuclear test in the remote, snowy northeast today, taking a crucial step toward its goal of building a bomb small enough to be fitted on a missile capable of striking the United States.
North Korea said the atomic test was merely its "first response" to what it called U.S. threats, and said it will continue with unspecified "second and third measures of greater intensity" if Washington maintains its hostility.
The underground test, which set off powerful seismic waves, drew immediate condemnation from Washington, the U.N. and others. Even its only major ally, China, voiced opposition.
On a large television screen in front of Pyongyang’s railway station, a North Korean state television broadcaster announces the news that North Korea conducted a nuclear test today.
President Barack Obama, who was scheduled to give a State of the Union address later today, said nuclear tests "do not make North Korea more secure."
Instead, North Korea has "increasingly isolated and impoverished its people through its ill-advised pursuit of weapons of mass destruction," he said in a statement.
North Korea claimed the device was smaller than in previous tests; Seoul said it likely produced a bigger explosion.
N.KOREA'S PURSUIT OF NUCLEAR WEAPONS
ROCKET LAUNCH (August): This early launch gets the world's attention, because it goes well beyond North Korea's known capability. The rocket, which hurtles over Japan, has an estimated potential range of 1,550 miles, but accuracy is reportedly poor with no meaningful strike capability.
ROCKET LAUNCH (July): A three-stage rocket with a potential range of 4,100 miles fizzles soon after liftoff, the U.S. and South Korea say. North Korea has never acknowledged the launch.
NUCLEAR TEST (October): North Korea detonates a nuclear device for the first time, but the yield is a very low 0.5 to 1 kiloton.
ROCKET LAUNCH (April): This launch is a partial success, with two of the three stages pushing the rocket out over the Pacific. The third stage fails, and, despite North Korea's claims of success, no satellite is put into orbit, the U.S. says.
NUCLEAR TEST (May): Second detonation of a nuclear device is a partial success with a larger yield of 2 to 6 kilotons, but still below the 10 kilotons that experts consider a successful blast.
ROCKET LAUNCH (April 2012): Launch of Unha-3 rocket, with a potential range of 6,200 miles ends in embarrassing failure, splintering into pieces over the Yellow Sea soon after takeoff.
ROCKET LAUNCH (December 2012): This time, the rocket succeeds in launching a satellite into space. Its range, though questioned by some experts, in theory puts the U.S. West Coast, Hawaii, Australia and eastern Europe within striking distance.
NUCLEAR TEST (February 2013): North Korea says it detonates a miniaturized nuclear device. If true, this would be an advance, as North Korea needs to master the technology to make a nuclear device small enough to mount on a missile.
The test was a defiant response to U.N. orders to shut down atomic activity or face more sanctions and international isolation.
It will likely draw more sanctions from the United States and other countries at a time when North Korea is trying to rebuild its moribund economy and expand its engagement with the outside world.
Several U.N. resolutions bar North Korea from conducting nuclear or missile tests because the U.N. Security Council considers Pyongyang a would-be proliferator of weapons of mass destruction and its nuclear testing a threat to international peace and stability.
North Korea dismisses that as a double standard, and claims the right to build nuclear weapons as a defense against the United States, which has been seen as enemy No. 1 since the 1950-53 Korean War. The U.S. stations more than 28,000 troops in South Korea to protect its ally.